Office arrives on iOS, but only for the iPhone

Microsoft has finally released its Office Mobile suite for iOS, but there's a catch: it's iPhone-only, and it's only accessible through an Office 365 subscription, so there's effectively no free version.

That means there continues to be no version of Office for iPad users at all, with Microsoft choosing to hold onto one of the few strong cards it has in the tablet market for now.

Office Mobile for iOS is similar to the Windows Phone version, and supports Word, Excel and PowerPoint documents, though only the first two can be created from scratch.

Editing tools are said to be an improvement on the Windows Phone version – for instance, changes you've chosen to undo update in real time within documents, which isn't the case in the WP app.

Changes to documents are synced up to SkyDrive, and fully integrate with Office Web Apps and Office 2013 on the desktop.

The requirement for an Office 365 subscription will be an annoyance for some, but Apple does well out of the deal, since the process of subscribing after installing the Office app initially makes it an in-app purchase, so require a cut to go directly to Apple.

Microsoft says it won't be releasing an iPad version of Office Mobile at all, so Office Web Apps will have to do for now.

Office Mobile for Office 365 subscribers will be available via iTunes in the next few days (so far only the US version has been released). It's optimised for the iPhone 5, but will run on any iPhone running iOS 6.1 or newer.